Spindle drive assembly and vehicle flap with a spindle drive assembly

ABSTRACT

A spindle drive assembly for opening and/or closing a vehicle flap is described, having a spindle drive assembly housing extending along a spindle drive axis and a spindle drive motor arranged in the spindle drive assembly housing. The motor shaft of the spindle drive motor is arranged substantially coaxially with the spindle drive axis. Furthermore, the spindle drive motor is supported in the spindle drive assembly housing in a rotationally fixed manner in relation to the spindle drive axis by means of an interlocking fit. In addition, a vehicle flap with such a spindle drive assembly is presented.

The invention relates to a spindle drive assembly for opening and/orclosing a vehicle flap.

The invention further relates to a vehicle flap, in particular a vehiclehatch or tailgate or a vehicle trunk lid, with such a spindle driveassembly.

Vehicle flaps and spindle drive assemblies of the type initiallymentioned are known from the prior art.

The known spindle drive assemblies generally comprise an electricspindle drive by means of which the associated vehicle flap can beopened and/or closed. This means that a user of an associated vehicle nolonger needs to manually carry out the opening and/or closing. The useronly needs to send an open or close command to the spindle driveassembly, which he/she can do, for example, via a radio remote controlor via a switch arranged in the vehicle. A foot switch which is arrangedon the outside of the vehicle and can operate without contact can alsobe used.

Such spindle drive assemblies have to be able to reliably perform alarge number of opening and/or closing movements. At the same time, inthe field of spindle drive assemblies, the aim is always to constructthem as simply as possible, as a result of which a cost-effectivemanufacture is to be ensured. Obviously, there is a conflict ofobjectives between these requirements, so that known spindle driveassemblies that are especially reliable cannot usually be manufacturedparticularly cost-effectively, and vice versa.

The object of the invention is to overcome this conflict of objectivesand to indicate a spindle drive assembly which can be manufacturedsimply and cost-effectively and which also operates particularlyreliably.

The object is achieved by a spindle drive assembly of the type initiallymentioned, in which a spindle drive assembly housing extends along aspindle drive axis, and a spindle drive motor which is arranged in thespindle drive assembly housing and the motor shaft of which is arrangedsubstantially coaxially with the spindle drive axis is supported in thespindle drive assembly housing in a rotationally fixed manner inrelation to the spindle drive axis by means of an interlocking fit. Thissupport by an interlocking fit serves, among other things, to support orreact to the driving torque of the spindle drive motor in the spindledrive assembly housing. Interlocking elements can be manufacturedparticularly simply and with little effort on the spindle drive motorand on the spindle drive assembly housing, so that the spindle driveassembly altogether can be manufactured comparatively simply and withlittle effort. Moreover, an interlocking fit functions particularlyreliably. In particular, unlike a frictional connection, for example, itis not subject to aging or loosening phenomena. This ensures a longservice life of the spindle drive assembly.

In one embodiment, the spindle drive assembly housing comprises ahousing cap and the spindle drive motor is supported at the housing capin a rotationally fixed manner. The housing cap, which is a componentpart of the spindle drive assembly housing, is more particularlyconnected with a housing body so as to be rotationally fixed. Forexample, the housing cap is laser welded to the housing body. Thus, inthis embodiment as well, a reliable mounting of the spindle drive motoris ensured. This allows the spindle drive assembly to be operatedreliably. Furthermore, the housing cap can usually be designedrelatively freely, so that an interlocking element on the housing capside can be realized particularly easily and cost-effectively.

Preferably, the housing cap closes the spindle drive assembly housingaxially on an end side. In particular, this provides a watertight anddustproof spindle drive assembly housing. It protects the components ofthe spindle drive assembly particularly effectively against anyundesirable environmental influences.

The spindle drive motor may be supported in the spindle drive assemblyhousing by means of at least one damping element. Vibrations emanatingfrom the spindle drive motor can thus be effectively damped before theyare introduced into the spindle drive assembly housing. In other words,the spindle drive motor is vibration-decoupled from the spindle driveassembly housing. During operation of the spindle drive assembly, thespindle drive assembly housing therefore is, in particular, free ofvibrations or exhibits only minor vibrations. In addition, a noiseradiation of the spindle drive motor is reduced or prevented by thedamping elements. The result is a particularly quiet spindle driveassembly that can be operated with low vibration. Such an assembly isperceived as being of high quality. Moreover, it operates reliably.

In one variant, the spindle drive motor is supported in the spindledrive assembly housing by means of a motor housing. The interlockingelement on the spindle drive motor side is thus provided at the motorhousing, more precisely at a brush housing of the spindle drive motor.Such an interlocking element can be manufactured there with littleeffort. In this way, an effective torque support is also ensured. Thesame applies to the fastening of the spindle drive motor in the spindledrive assembly housing.

In this context, the motor housing may have at least two anti-rotationprojections provided thereon which, in the mounted state of the spindledrive motor, extend substantially along the spindle drive axis andengage in associated recesses provided on the spindle drive assemblyhousing. The anti-rotation projections feature a distance of greaterthan zero from the spindle drive axis. Projections and recesses aresimple and cost-effective to produce.

The motor housing is preferably made from a plastic material.

Preferably, the anti-rotation projections are circular cylindrical, withassociated circular cylinder center axes extending substantiallyparallel to the spindle drive axis in the mounted state of the spindledrive motor. Such anti-rotation projections are particularly simple toproduce. Furthermore, they can be simply inserted into associatedrecesses during assembly.

The anti-rotation projections may engage in the recesses via elasticdamping caps arranged on the anti-rotation projections or via elasticdamping elements arranged in the recesses. In this way, a vibrationdecoupling or at least a vibration damping between the spindle drivemotor and the spindle drive assembly housing is achieved. The dampingelements have a particularly simple geometry.

Preferably, the damping elements are made from an elastomer.

In one variant, the anti-rotation projections are provided on an axialend side of the spindle drive motor facing away from the motor shaft. Inother words, the anti-rotation projections are provided on the rear sideof the spindle drive motor. In this way, a mutual interference betweenthe rotationally fixed mounting of the spindle drive motor and thetorque collection from the motor shaft of the spindle drive motor iseffectively avoided.

In addition, a first electrical power connection of the spindle drivemotor and/or a second electrical power connection of the spindle drivemotor and/or a sensor connection of the spindle drive motor may beprovided on an axial end side of the spindle drive motor facing awayfrom the motor shaft. Since the anti-rotation projections can bedesigned to be comparatively small, a sufficiently large installationspace remains free for power connections and/or sensor connections. Thisallows the spindle drive motor to be constructed to be relativelycompact. The arrangement of the connections on the axial end side makesthem particularly easily accessible, in particular within the scope ofthe assembly process.

Furthermore, the object is achieved by a vehicle flap of the typeinitially mentioned, in particular a vehicle hatch or tailgate orvehicle trunk lid, which includes a spindle drive assembly according tothe invention. Since the spindle drive assembly is structured in asimple and cost-effective manner, a vehicle flap fitted with it isconsequently also structured to be comparatively simple andcost-effective. Furthermore, such a vehicle flap is particularlyreliable in operation.

In addition to the above-mentioned vehicle flaps, luggage flaps ortailgates of sport utility vehicles or commercial vehicles may also befitted with a spindle drive assembly according to the invention. Thesame applies to engine hoods and vehicle front gates.

The invention will be discussed below with reference to an exemplaryembodiment shown in the accompanying drawings, in which:

FIG. 1 schematically shows a vehicle flap according to the inventionwith a spindle drive assembly according to the invention that isassembled by means of a method according to the invention;

FIG. 2 shows the spindle drive assembly from FIG. 1 in a schematicsectional view;

FIG. 3 shows the spindle drive assembly from FIG. 1 in an explodedrepresentation;

FIG. 4 shows the spindle drive assembly from FIG. 1 in a sectionaldetail view;

FIG. 5 shows a spindle drive motor of the spindle drive assembly fromFIG. 1 in a perspective view;

FIG. 6 schematically shows the interaction of the spindle drive motorfrom FIG. 5 with a spindle drive assembly housing in a partly sectionalillustration;

FIG. 7 schematically shows an end view of the spindle drive motor fromFIGS. 5 and 6 and of a housing cap adapted to be connected with thespindle drive motor;

FIG. 8 shows an exploded illustration of a two-stage epicyclic gearingof the spindle drive assembly from FIG. 1, which can be assembled bymeans of a method according to the invention;

FIG. 9 shows a further exploded illustration of the two-stage epicyclicgearing of the spindle drive assembly from FIG. 1, with the epicyclicgearing partly assembled by means of a method according to theinvention;

FIG. 10 shows an exploded illustration of the spindle drive assemblyfrom FIG. 1, comprising a two-stage epicyclic gearing, a coupling, ahysteresis brake and a spindle drive motor;

FIG. 11 shows a spindle unit of the spindle drive assembly from FIG. 1in an exploded illustration;

FIG. 12 shows a detail of the spindle unit from FIG. 11;

FIG. 13 shows a detail of the spindle drive assembly from FIG. 1 in asectional illustration; and

FIG. 14 shows a further detail of the spindle drive assembly from FIG. 1in a sectional illustration.

FIG. 1 shows a vehicle flap 10, which in the present case is a vehiclehatch or liftgate, having a spindle drive assembly 12 by means of whichthe vehicle flap 10 can be opened and/or closed.

The spindle drive assembly 12 comprises a spindle drive assembly housing14 that extends along a spindle drive axis 16.

As can be seen in particular by reference to FIG. 2, a motor gear unit18, only schematically illustrated in FIG. 2, and a spindle unit 20,also only schematically illustrated in FIG. 2, are arranged in thespindle drive assembly housing 14.

The spindle drive assembly housing 14 here comprises, between its axialends 14 a, 14 b, a stop section 22 acting axially on both sides.

The motor gear unit 18 is arranged on a first axial side 22 a of thestop section 22 and the spindle unit 20 is arranged on a second axialside 22 b opposite the first axial side 22 a.

Both the motor gear unit 18 and the spindle unit 20 rest against thestop section 22.

In the illustrated embodiment (see in particular FIGS. 3 and 4), themotor gear unit 18 is supported in the spindle drive assembly housing 14by means of two damping elements 24 a, 24 b made from an elastomer.

In addition to a spindle 26 and a spindle nut 28 coupled thereto, thespindle unit 20 comprises a guide tube 30.

In the illustrated embodiment, the guide tube 30 is fastened to thespindle drive assembly housing 14. More precisely, the guide tube 30 islaser welded to the spindle drive assembly housing 14. The laser weldseam 32 is drawn in only schematically here.

The stop section 22 is produced in one piece with the spindle driveassembly housing 14.

Here, the spindle drive assembly housing 14 is made from a plasticmaterial.

In the present case, the stop section 22 is manufactured by injectionmolding the spindle drive assembly housing 14.

The spindle drive assembly housing 14 additionally comprises a housingcap 14 c. It closes the spindle drive assembly housing 14 on the motorgear unit side.

The housing cap 14 c and the spindle drive assembly housing 14 are laserwelded. The laser weld seam 34 is again drawn only schematically here.

The assembly of the spindle drive assembly 12 is performed as follows.

First, the spindle drive assembly housing 14 is provided.

Then the motor gear unit 18 is inserted into the spindle drive assemblyhousing 14 starting from a first axial side of the spindle driveassembly housing 14 on which, in the example shown, the axial end 14 bis located.

In doing so, the motor gear unit 18 is placed against the first axialside 22 a of the stop section 22.

The spindle unit 20 is inserted into the spindle drive assembly housing14 from a second axial side 22 b of the spindle drive assembly housing14 opposite to the first axial side thereof. In the illustratedembodiment, the axial end 14 a is located on this side.

The spindle unit 20 is placed against the second axial side 22 b of thestop section 22.

It is irrelevant to the assembly process whether first the motor gearunit 18 or first the spindle unit 20 is mounted to the spindle driveassembly housing 14. The motor gear unit 18 and the spindle unit 20 mayalso be mounted essentially simultaneously.

When the spindle unit 20 has been inserted in the spindle drive assemblyhousing 14, it is fastened in it. In the illustrated embodiment, thespindle unit 20 comprises a guide tube 30 that is fastened to thespindle drive assembly housing 14 by means of the laser weld seam 32.

That is, the spindle drive assembly housing 14 and the guide tube 30 arelaser welded.

Subsequently, the spindle drive assembly housing 14 is closed at its end14 b using a housing cap 14 c. In this context, the spindle driveassembly housing 14 is laser welded to the housing cap 14 c.

The motor gear unit 18 comprises a spindle drive motor 36, which iscoupled to a gearing 40 via a motor shaft 38.

FIGS. 5-7 show the spindle drive motor 36 in detail.

With the motor gear unit 18 arranged within the spindle drive assemblyhousing 14, the spindle drive motor 36 is also positioned within thespindle drive assembly housing 14. The motor shaft 38 here issubstantially coaxial with the spindle drive axis 16.

In addition, the spindle drive motor 36 and thus the motor gear unit 18are supported in the spindle drive assembly housing 14 so as to berotationally fixed with respect to the spindle drive axis 16 by means ofan interlocking fit.

More precisely, the spindle drive motor 36 is supported at the housingcap 14 c in a rotationally fixed manner by means of an interlocking fit,the housing cap being a component part of the spindle drive assemblyhousing 14.

The rotationally fixed mounting is provided here by means of a motorhousing 42 of the spindle drive motor 36.

In the illustrated embodiment, it has two anti-rotation projections 44a, 44 b provided thereon which, in the assembled state of the spindledrive motor 36 and thus also of the motor gear unit 18, extendsubstantially along the spindle drive axis 16.

In the present case, the anti-rotation projections 44 a, 44 b arecircular cylindrical, with the associated circular cylinder center axes46 a, 46 b extending substantially parallel to the spindle drive axis 16in the mounted state of the spindle drive motor 36.

The anti-rotation projections 44 a, 44 b are provided on an axial endside 48 of the spindle drive motor 36 facing away from the motor shaft38. In the assembled state, the anti-rotation projections 44 a, 44 b arethus positioned on a side of the spindle drive motor 36 opposite to thegearing 40.

In the assembled state, the anti-rotation projections 44 a, 44 b engagein associated recesses 50 a, 50 b provided on the spindle drive assemblyhousing 14. In the illustrated embodiment, the recesses 50 a, 50 b areprovided on the housing cap 14 c.

More precisely, in the illustrated embodiment, the recesses 50 a, 50 bare provided on the damping element 24 b, which is connected to thehousing cap 14 c in a rotationally fixed manner.

As an alternative, the anti-rotation projections 44 a, 44 b may engagein the recesses 50 a, 50 b via elastic damping caps arranged on theanti-rotation projections 44 a, 44 b or via elastic damping elementsarranged in the recesses 50 a, 50 b.

As is apparent in particular by reference to FIG. 5, in the illustratedembodiment, besides the anti-rotation projections 44 a, 44 b, a firstelectrical power connection 52, a second electrical power connection 54and a sensor connection 56 are additionally provided on the axial endside 48 of the spindle drive motor 36.

FIGS. 8 and 9 show the gearing 40 in detail.

It can be seen here that the gearing 40 is a two-stage epicyclic gearing58.

In this context, it comprises a first epicyclic gearing stage 58 a,which is also referred to as motor-side or drive-side epicyclic gearingstage 58 a, and a second epicyclic gearing stage 58 b, which is alsoreferred to as spindle-side or driven-side epicyclic gearing stage 58 b.

The epicyclic gearing 58 has helical toothings. Both epicyclic gearingstages 58 a, 58 b have helical toothings in the same direction.

Moreover, the two-stage epicyclic gearing 58 comprises merely onesingle, singular planet carrier 60, which is thus part of both epicyclicgearing stages 58 a, 58 b.

Furthermore, both the motor-side epicyclic gearing stage 58 a and thespindle-side epicyclic gearing stage 58 b comprise an equal number ofplanet gears 62 a, 62 b. In the exemplary embodiment shown, each of theepicyclic gearing stages 58 a, 58 b comprises four planet gears 62 a, 62b.

One respective planet gear 62 a of the first epicyclic gearing stage 58a and one respective planet gear 62 b of the second epicyclic gearingstage 58 b are mounted on a shared planet gear pin 64.

The planet gears 62 a, 62 b mounted on a shared planet gear pin 64 areconnected to each other for joint rotation.

The epicyclic gearing 58 operates as follows.

The motor shaft 38 is rotationally coupled to a sun gear 66 of themotor-side epicyclic gearing stage 58 a. Thus, the sun gear 66constitutes the drive or torque input of the epicyclic gearing 58.

Since this coupling is effected via a clutch or coupling 68, strictlyspeaking a gearing input shaft 70 is coupled to the sun gear 66.However, it may be regarded as a continuation of the motor shaft 38.

In the illustrated embodiment, the coupling 68 is an Oldham coupling forcompensating an axial offset. FIG. 8 only shows a gearing-side couplingpart 69, which is connected with the gearing input shaft 70.

The sun gear 66 cooperates with the planet gears 62 a of the motor-sideepicyclic gearing stage 58 a, which in turn are coupled to a ring gear72 of the motor-side epicyclic gearing stage 58 a.

The ring gear 72 is mounted so as to be rotationally fixed and axiallyfixed in the spindle drive assembly housing 14 and/or in an epicyclicgearing housing 74. This means that the ring gear 72 is substantiallypositioned fixed in space.

The motor-side epicyclic gearing stage 58 a is coupled to thespindle-side epicyclic gearing stage 58 b both via the singular planetcarrier 60 and via the one-piece planet gears 62 a, 62 b.

Here, the spindle-side epicyclic gearing stage 58 b is constructedwithout a sun gear.

The planet gears 62 b of the spindle-side epicyclic gearing stage 58 bare only radially supported on an axial bearing extension 76 of the sungear shaft of the motor-side epicyclic gearing stage 58 a. The sun gearshaft here corresponds to the gearing input shaft 70.

The planet gears 62 b of the spindle-side epicyclic gearing stage 58 bare further coupled to a ring gear 78 of the spindle-side epicyclicgearing stage 58 b.

This ring gear 78 is rotationally coupled to the spindle 26 by means ofa coupling 80. The ring gear 78 is mounted for rotation in the spindledrive assembly housing 14 and/or in the epicyclic gearing housing 74.

The ring gear 78 thus constitutes the output or torque output of theepicyclic gearing 58.

The epicyclic gearing 58 can be assembled as follows.

First, all planet gears 62 a, 62 b of the two epicyclic gearing stages58 a, 58 b are fitted in the singular planet carrier 60.

Subsequently, the planet carrier 60 is inserted into the ring gear 72 ofthe drive-side epicyclic gearing stage 58 a or into the ring gear 78 ofthe driven-side epicyclic gearing stage 58 b.

Then, the respective other ring gear, that is, the ring gear 78 or thering gear 72, is placed on this component assembly.

Thereafter, the epicyclic gearing housing 74 is provided and connectedwith the ring gear 72.

In the illustrated embodiment, the epicyclic gearing housing 74 is laserwelded to the ring gear 72 in a lap joint. For this purpose, theepicyclic gearing housing 74 is laser light transmissive.

For the spindle drive assembly 12 to emit noises when operating that amotor vehicle user will perceive as pleasant, the ratio of the number ofteeth of each of the planet gears 62 a of the first epicyclic gearingstage 58 a to the number of teeth of each of the planet gears 62 b ofthe second epicyclic gearing stage 58 b is selected to be 2:1.

In the illustrated embodiment, each planet gear 62 a of the firstepicyclic gearing stage 58 a comprises twelve teeth and each planet gear62 b of the second epicyclic gearing stage 58 b comprises six teeth.

The ratio of 2:1 corresponds to the interval of an octave when it isbased on a ratio of sound frequencies.

Given that the sound frequency emitted by the first epicyclic gearingstage 58 a is decisively determined by the number of teeth of the planetgears 62 a of the first epicyclic gearing stage 58 a and the soundfrequency emitted by the second epicyclic gearing stage 58 b isdecisively determined by the number of teeth of the planet gears 62 b ofthe second epicyclic gearing stage 58 b, the spindle drive assembly 12thus emits sound frequencies in operation which form an octave. This isperceived as particularly pleasant by vehicle users.

In addition, a vehicle user will associate such pleasant noises with ahigh level of quality of spindle drive assembly 12.

Alternatively, the ratio of the number of teeth of each of the planetgears 62 a of the first epicyclic gearing stage and the number of teethof each of the planet gears 62 b of the second epicyclic gearing stagemay also be selected to be 3:2, 4:3, 5:4, or 6:5.

The emitted sound frequencies then form a fifth, a fourth, a major thirdor a minor third, respectively. These intervals are also perceived aspleasant by humans.

Generally speaking, the ratio of the number of teeth of each planet gear62 a of the first epicyclic gearing stage 58 a to the number of teeth ofeach planet gear 62 b of the second epicyclic gearing stage 58 b isselected such that, in operation, a first sound frequency that isemitted by the first epicyclic gearing stage 58 a differs by an integermultiple of a semitone from a second sound frequency that is emitted bythe second epicyclic gearing stage 58 b.

The preferred embodiment of the octave comprises twelve semitone steps,that of the fifth seven, that of the fourth five, that of the majorthird four and that of the minor third three.

The coupling of the spindle drive motor 36 to the gearing 40, moreprecisely to the two-stage epicyclic gearing 58, is illustrated indetail in FIG. 10. Here, the coupling 68 compensating an axial offsetand a hysteresis brake 82 are drivingly interposed between the spindledrive motor 36 and the gearing 40.

As already mentioned, the coupling 68 is an Oldham coupling andcomprises a coupling part 84 on the drive motor side and the couplingpart 69 on the gearing side (see FIG. 8).

The two coupling parts 69, 84 are connected to each other via anintermediate coupling part 86 such that the motor shaft 38 and thegearing input shaft 70 are connected to each other for joint rotation.

At the same time, when in the mounted state, the intermediate couplingpart 86 is displaceable in relation to the drive motor-side couplingpart 84 along a direction 88.

The gearing-side coupling part 69 is displaceable in relation to theintermediate coupling part 86 along a direction 90.

The direction 88 and the direction 90 are substantially orthogonal toeach other here. In this way, an axial offset between the motor shaft 38and the gearing input shaft 70 can be compensated in line with theoperating principle of an Oldham coupling.

The hysteresis brake 82 comprises a stationary hysteresis brakecomponent 92, which is fastened to the spindle drive assembly housing 14and/or to the epicyclic gearing housing 74.

Furthermore, the hysteresis brake 82 includes a rotatable hysteresisbrake component 94 rotationally coupled to the motor shaft 38.

The hysteresis brake component 94 is fastened to or integrated in thedrive motor-side coupling part 84. More particularly, the rotatablehysteresis brake component 94 is injected into the drive motor-sidecoupling part 84.

When the spindle drive assembly 12 is viewed perpendicularly to thespindle drive axis 16, the coupling 68 is arranged substantiallycompletely within the hysteresis brake 82 in the axial direction, inparticular within the stationary hysteresis brake component 92. Thestructure of the coupling 68 and the hysteresis brake 82 is thereforeespecially compact.

FIGS. 11-14 show the spindle unit 20 in detail.

Here, a stop assembly 96 arranged at one axial end of the spindle 26 isadapted to limit a mobility of the spindle nut 28 along the spindledrive axis 16. Specifically, in this way the spindle nut 28 is preventedfrom moving beyond the end of the spindle 26.

The stop assembly 96 comprises a plastically deformable energyabsorption component 97, which in the illustrated embodiment is in theform of an energy absorption sleeve 98, which surrounds the spindle 26substantially coaxially.

This means that the energy absorption sleeve 98 is mounted at thespindle 26.

The energy absorption sleeve 98 is arranged between a bearing washer 100on the spindle end side and the spindle nut 28 along the spindle driveaxis 16 (see in particular FIG. 14).

Moreover, a bearing member 102 is provided between the energy absorptionsleeve 98 and the bearing washer 100 to support the spindle 26 at thespindle drive assembly housing 14.

In addition, a thrust washer 104 that is axially displaceable on thespindle 26 is arranged between the energy absorption sleeve 98 and thespindle nut 28.

In the illustrated embodiment, both the bearing washer 100 and thethrust washer 104 are made of a metal material.

At each of its two axial ends, the energy absorption sleeve 98 has arespective collar 106 a, 106 b configured as a force introductioncollar.

A deformation section 108 adapted to be upset in the direction of thespindle drive axis 16 is positioned between the collars 106 a, 106 b.

In the illustrated embodiment, the deformation section includes only onesingle deformation portion. In alternative embodiments, however, it maycomprise several, in particular two, deformation portions, with bothdeformation portions being adapted to be upset in the direction of thespindle drive axis 16.

In a regular operation of the spindle drive assembly 12, the energyabsorption sleeve 98 is essentially plastically undeformed (see inparticular FIGS. 12 to 14). In regular operation, preferably loads onthe energy absorption sleeve 98 occur here which exclusively involveforces of less than 750 N.

A load on the energy absorption sleeve 98 with a force of essentiallymore than 3000 N constitutes an overload event for the illustratedembodiment. This causes the energy absorption sleeve 98 to beplastically deformed.

Such an overload event occurs when the spindle nut 28 runs up againstthe stop assembly 96, more precisely the energy absorption sleeve 98, attoo high a speed and/or too high a force.

This may happen, for example, when the hysteresis brake 82 is defective.

An overload event may also occur during installation of the vehicle flap10 when the spindle drive assembly 12 is already connected with thevehicle flap 10, but further components of the vehicle flap 10 are stillmissing. The vehicle flap 10 is then significantly more lightweight thanduring operation of an associated vehicle, for which the spindle driveassembly 12 is designed. In this connection, the spindle drive assembly12 may be transferred to an open position by means of a spring that isnot further specified. Due to the relatively low weight of the vehicleflap, the spindle nut 28 will then run up against the stop assembly 96too quickly.

In all overload events, the energy absorption sleeve 98 absorbs theenergy resulting from the excessive speed and/or excessive force andthereby protects the other components of the spindle drive assemblygroup 12 from damage.

FIG. 14 illustrates the spindle nut 28 resting against the energyabsorption sleeve 98. However, for reasons of greater clarity, thelatter is shown in its plastically undeformed state.

A subsequent operation of the spindle drive assembly 12 in which theopening and closing of the vehicle flap 10 is still possible without anyproblems is also referred to as an overload sequential operation. Inthis operating condition the energy absorption sleeve 98 is plasticallydeformed (not illustrated).

In the event that the energy absorption sleeve 98 comprises a pluralityof deformation portions, only one of the deformation portions isplastically deformed in the overload sequential operation.

In case a second overload event occurs subsequently and the energyabsorption sleeve 98 comprises a second deformation portion, the latterwill deform plastically due to the second overload event. Subsequently,the spindle drive assembly 12 will enter a secondary overload sequentialoperation, in which the opening and closing of the vehicle flap 10 bymeans of the spindle drive assembly 12 continues to be ensured.

1. A spindle drive assembly for opening and/or closing a vehicle flap,comprising a spindle drive assembly housing extending along a spindledrive axis and a spindle drive motor which is arranged in the spindledrive assembly housing and the motor shaft of which is arrangedsubstantially coaxially with the spindle drive axis, wherein the spindledrive motor is supported in the spindle drive assembly housing in arotationally fixed manner in relation to the spindle drive axis by meansof an interlocking fit.
 2. The spindle drive assembly according to claim1, characterized in that the spindle drive assembly housing comprises ahousing cap and the spindle drive motor is supported at the housing capin a rotationally fixed manner.
 3. The spindle drive assembly accordingto claim 2, characterized in that the housing cap closes the spindledrive assembly housing axially on an end side.
 4. The spindle driveassembly according to claim 1, characterized in that the spindle drivemotor is supported in the spindle drive assembly housing by means of atleast one damping element.
 5. The spindle drive assembly according toclaim 1, characterized in that the spindle drive motor is supported inthe spindle drive assembly housing by means of a motor housing.
 6. Thespindle drive assembly according to claim 5, characterized in that themotor housing has at least two anti-rotation projections providedthereon which, in the mounted state of the spindle drive motor, extendsubstantially along the spindle drive axis and engage in associatedrecesses provided on the spindle drive assembly housing.
 7. The spindledrive assembly according to claim 6, characterized in that theanti-rotation projections are circular cylindrical, with associatedcircular cylinder center axes extending substantially parallel to thespindle drive axis in the mounted state of the spindle drive motor. 8.The spindle drive assembly according to claim 6 or 7, characterized inthat the anti-rotation projections engage in the recesses via elasticdamping caps arranged on the anti-rotation projections or via elasticdamping elements arranged in the recesses.
 9. The spindle drive assemblyaccording to claim 6, characterized in that the anti-rotationprojections are provided on an axial end side of the spindle drive motorfacing away from the motor shaft.
 10. The spindle drive assemblyaccording to claim 1, characterized in that a first electrical powerconnection of the spindle drive motor and/or a second electrical powerconnection of the spindle drive motor and/or a sensor connection of thespindle drive motor are provided on an axial end side of the spindledrive motor facing away from the motor shaft.
 11. A vehicle flapcomprising a spindle drive assembly according to claim
 1. 12. A vehicleflap according to claim 11 that is a vehicle hatch or tailgate orvehicle trunk lid.